EEPROM is a non-volatile type of memory that is used in applications that require a small footprint, board space; byte level erase, write or read; low voltage and current; and low availability of microcontroller. The field where EEPROM can be used are:

  • Automotive;
  • Industrial;
  • Telecommunications;
  • Consumer. 

EEPROM is a read/write memory type indirectly addressed via Special Function Registers:

  • EECON1 – contains control bits;
  • EECON2 – register, initiating read/write function;
  • EEDATA – contains 8-bit write/read data;
  • EEADR – contains address accessed in the EEPROM. It can access up to 256 locations of EEPROM data.

This data allows byte read and write, so as soon as the bytes access the location, it erases part of data before writing it. Write time varies depending on different factors, and is controlled by the on-chip timer.

Cases where EEPROM is used:

  • Storing selectors and controls;
  • Recovery events;
  • Power down events;
  • Maintenance logs;
  • And other operational actions.

EEPROM can be serial and parallel. Serial EEPROM takes only ten percent of board space. Parallel EEPROM requires more I/O lines from the microcontroller. Serial EEPROM is limited with READ speed. And limitation is protocol. Find out about Serial EEPROM protocols in our next post.